Flip chip joint-in-via architecture on flexible substrates with Au-Sn interdiffusion bonding

Abstract

Pad pitch on substrate has been identified as a difficult flip-chip, which makes it a challenge to keep up with the microelectronic packaging revolution. This study proposes a joint-in-via architecture to meet this challenge but this research is hindered by the flux residues of conventional soldering. This study conceptualises the joint-in-via architecture and develops a fluxless bonding technique with its mechanism and reliability uncovered.